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author | Amit Daniel Kachhap <amit.kachhap@arm.com> | 2022-11-03 13:52:32 +0530 |
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committer | Catalin Marinas <catalin.marinas@arm.com> | 2022-11-03 18:04:56 +0000 |
commit | 85f1506337f0c79a4955edfeee86a18628e3735f (patch) | |
tree | 4d2573492c343b39586e1984390dca58b4d7a2dc /Documentation/arm64/cpu-feature-registers.rst | |
parent | 024f4b2e1f874934943eb2d3d288ebc52c79f55c (diff) | |
download | lwn-85f1506337f0c79a4955edfeee86a18628e3735f.tar.gz lwn-85f1506337f0c79a4955edfeee86a18628e3735f.zip |
arm64: cpufeature: Fix the visibility of compat hwcaps
Commit 237405ebef58 ("arm64: cpufeature: Force HWCAP to be based on the
sysreg visible to user-space") forced the hwcaps to use sanitised
user-space view of the id registers. However, the ID register structures
used to select few compat cpufeatures (vfp, crc32, ...) are masked and
hence such hwcaps do not appear in /proc/cpuinfo anymore for PER_LINUX32
personality.
Add the ID register structures explicitly and set the relevant entry as
visible. As these ID registers are now of type visible so make them
available in 64-bit userspace by making necessary changes in register
emulation logic and documentation.
While at it, update the comment for structure ftr_generic_32bits[] which
lists the ID register that use it.
Fixes: 237405ebef58 ("arm64: cpufeature: Force HWCAP to be based on the sysreg visible to user-space")
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Link: https://lore.kernel.org/r/20221103082232.19189-1-amit.kachhap@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'Documentation/arm64/cpu-feature-registers.rst')
-rw-r--r-- | Documentation/arm64/cpu-feature-registers.rst | 38 |
1 files changed, 37 insertions, 1 deletions
diff --git a/Documentation/arm64/cpu-feature-registers.rst b/Documentation/arm64/cpu-feature-registers.rst index 04ba83e1965f..c7adc7897df6 100644 --- a/Documentation/arm64/cpu-feature-registers.rst +++ b/Documentation/arm64/cpu-feature-registers.rst @@ -92,7 +92,7 @@ operation if the source belongs to the supported system register space. The infrastructure emulates only the following system register space:: - Op0=3, Op1=0, CRn=0, CRm=0,4,5,6,7 + Op0=3, Op1=0, CRn=0, CRm=0,2,3,4,5,6,7 (See Table C5-6 'System instruction encodings for non-Debug System register accesses' in ARMv8 ARM DDI 0487A.h, for the list of @@ -293,6 +293,42 @@ infrastructure: | WFXT | [3-0] | y | +------------------------------+---------+---------+ + 10) MVFR0_EL1 - AArch32 Media and VFP Feature Register 0 + + +------------------------------+---------+---------+ + | Name | bits | visible | + +------------------------------+---------+---------+ + | FPDP | [11-8] | y | + +------------------------------+---------+---------+ + + 11) MVFR1_EL1 - AArch32 Media and VFP Feature Register 1 + + +------------------------------+---------+---------+ + | Name | bits | visible | + +------------------------------+---------+---------+ + | SIMDFMAC | [31-28] | y | + +------------------------------+---------+---------+ + | SIMDSP | [19-16] | y | + +------------------------------+---------+---------+ + | SIMDInt | [15-12] | y | + +------------------------------+---------+---------+ + | SIMDLS | [11-8] | y | + +------------------------------+---------+---------+ + + 12) ID_ISAR5_EL1 - AArch32 Instruction Set Attribute Register 5 + + +------------------------------+---------+---------+ + | Name | bits | visible | + +------------------------------+---------+---------+ + | CRC32 | [19-16] | y | + +------------------------------+---------+---------+ + | SHA2 | [15-12] | y | + +------------------------------+---------+---------+ + | SHA1 | [11-8] | y | + +------------------------------+---------+---------+ + | AES | [7-4] | y | + +------------------------------+---------+---------+ + Appendix I: Example ------------------- |